It's so true - if a headphone sounds like a headphone, enjoy it. But try pushing it toward the sound of speakers and it will just start sounding muddy or whatever - something that's too complex to replicate with current technology.
Current technology includes the Smyth Realiser A8, which can, according to reliable reviewers, replicate the soundstage and other spatial qualities of a reference speaker system, albeit for a price - $3700, including the recommended Stax headphones.
I too fall into the "why bother" camp, headphones are headphones, but the Smyth does open up some interesting possibilities, including setting up a 7.1 surround environment using only one speaker for calibration purposes.
For the most edifying and least "gee whiz" description, check out "Linear Audio - Volume 7"
